Single-segment speed run of Gauntlet for NES as Elf done during January 2005. This game is a monster challenge, but I found the secret to speed-running it: You don't need to collect the clues! Normally, the game has you play through a bunch of extra rooms in order to piece together a code that opens the final stage (the "Vault"). However, I managed to see a pattern in the codes that could be used to decipher any combination, simply by looking at your password from after each treasure room. So no, even though it may look like I cheated at the end by using save states or something, I didn't!
The only thing I hate about Gauntlet is the randomness of the treasure rooms. As shown in the emulator run, it's better to be lucky than good. If you get a lot of easy exits, you'll get a faster time. Once you know the path through the game, that's really all there is to it. Still, I did have fun flying through the mazes with that speedy Elf, especially after he gets the speed potion! :)